server supports Resumed 0-RTT Handshake

[thekuwayama]

No description provided.

[thekuwayama]

https://tools.ietf.org/html/rfc8446#page-54

   A server which receives an "early_data" extension MUST behave in one
   of three ways:

   -  Ignore the extension and return a regular 1-RTT response.  The
      server then skips past early data by attempting to deprotect
      received records using the handshake traffic key, discarding
      records which fail deprotection (up to the configured
      max_early_data_size).  Once a record is deprotected successfully,
      it is treated as the start of the client's second flight and the
      server proceeds as with an ordinary 1-RTT handshake.

   -  Request that the client send another ClientHello by responding
      with a HelloRetryRequest.  A client MUST NOT include the
      "early_data" extension in its followup ClientHello.  The server
      then ignores early data by skipping all records with an external
      content type of "application_data" (indicating that they are
      encrypted), up to the configured max_early_data_size.

   -  Return its own "early_data" extension in EncryptedExtensions,
      indicating that it intends to process the early data.  It is not
      possible for the server to accept only a subset of the early data
      messages.  Even though the server sends a message accepting early
      data, the actual early data itself may already be in flight by the
      time the server generates this message.